1. Field of the Invention
This invention relates to new and useful improvements in bag forming apparatus and more particularly to a novel tube former and a apparatus utilizing said tube former to produce a bag having a releasable side seam.
2. Brief Description of the Prior Art
In conventional bag former apparatus, thin tube stock is fed from feed rolls over a tube former and down through the tube portion of the bag former. The tube stock is converted from a sheet or strip form into a tube having an overlapping seam or a thin seam at the front which is sealed by a continuous heat sealing device positioned in front of and below the tube former. The tube which is formed is subsequently heat sealed crosswise by heat sealing bars positioned below the tube former to form the bottom of a bag. The bag is filled with its desired contents through the bag former tube. The filled bag, which is sealed at the bottom and still open at the top, is moved downward in the apparatus and heat sealing bars seal the top of the bag and the bottom of the next bag and cuts the finished and filled bag from the bag which still to be formed.
Leasure et al U.S. Pat. No. 3,133,390 discloses a bag forming apparatus having a tube former and sealing and cutting die.
Brown et al U.S. Pat. No. 3,918,235 discloses a process for continuously forming compartmented packages in which a sheet of plastic film is passed over a tube former and through the tube of the former to produce the desired structure followed by forming longitudinal heat seals by a plurality of sealing devices.
Hobart U.S. Pat. No. 3,948,153 discloses a tube former which forms a overlapping seal to the front of the bag.
Tanner U.S. Pat. No. 3,486,424 discloses a tube former for tube or bag forming machines having a wear insert.
Reed U.S. Pat. No. 3,257,228 discloses the use of adhesive strips to form releasable seals.
Kratzer et al U.S. Pat. No. 3,307,773 discloses a sandwich bag having a reclosable flap.